fixed bad changes to liquibase scripts, created a new changeset for them
Merge branch 'master' into ckozak/fix_liquibase_actkey_nullable

Conflicts:
	src/main/resources/db/changelog/changelog-create.xml
	src/main/resources/db/changelog/changelog-update.xml
Merge pull request #418 from candlepin/ckozak/fix_liquibase_actkey_nullable

fixed bad changes to liquibase scripts, created a new changeset for them